1. Field of the Invention
The present invention relates to a video interface for displaying an image on a display panel, more particularly to a system and method for driving display and high definition panels by distributed processing.
2. Related Art
A display image is generally processed by a graphics controller of a host device, for example a personal computer (PC) or the like, and sent to a display device. However, progress in display devices, such as, for example, a recent liquid crystal display (LCD) panel, has resulted in differences in processing capabilities between the host device and the display device. For example, referring to LCD panels, the definition of a panel has been increased, and high-resolution (ultra high-resolution) panels with very high pixel count have been put into practical use. In comparison with the resolution of prior panels, such as 1024×768 dots in XGA (eXtended Graphics Array), 1280×1024 dots in SXGA (Super eXtended Graphics Array), 1400×1050 dots in SXGA+ and 1600×1200 dots in UXGA (Ultra eXtended Graphics Array), the pixel count of the panels coming into practical use has increased greatly, for example, to 2048×1536 dots in QXGA (Quad eXtended Graphics Array), 2560×2048 dots in QSXGA (Quad Super eXtended Graphics Array) and 3200×2400 dots in QUXGA (Quad Ultra eXtended Graphics Array). These high-resolution, or ultra high-resolution, panels far exceed CRTs in definition. However, the power of the typical host system and graphics controller is not sufficient to keep up with the progress of panel technology and therefore the high-resolution panels cannot realize their potential definition. Performance of an image processing system as typified by a graphics controller is at most QXGA (2048×1536 dots) in terms of a general display function. For three dimensional (3D) computer graphics (CG) as typified by home video game machines, the performance of the image processing system shows a processing capability of merely a low pixel count of about 640×480 dots in VGA (Video Graphics Array). As described above, while the most advanced moving pictures still show a VGA grade pixel count, the panels that now can be manufactured show a pixel count several or several tens of times as high as that of the moving pictures. The disparity in processing capability has increased significantly.
Display devices as typified by the LCD panel have much smaller frames than ever, which are located around its display portion; and so-called tiling that makes panels up into a large panel, has been made possible. As a result, it is possible to further increase the pixel count of the display devices as well as the ultra high-resolution panels, and the difference in the processing capability between the host system and the display is even more significant.
Furthermore, in an attempt to keep the frame rate constant on the display panel side, when display video data transmitted from a host system (host side) is displayed on an ultra high-resolution display panel, as the grade of high resolution increases, the transfer rate on the video interface must be made greater. On the other hand, with reference to the video interface between the host system and the display system, instead of conventional analog interfaces, so-called digital interfaces such as LVDS (Low Voltage Differential Signaling), TMDS (Transition Minimized Differential Signaling) and GVIF (Gigabit Video InterFace) have been introduced. These use a digital data transmission system which operates at a low voltage. Therefore, increases in these transfer rates can be achieved by increasing the frequency of transfer clocks of the digital interface, and by doubling (Dual Channel) and quadrupling (Quadruple Channel) the number of signal lines of the video interface.
However, in the above-described way, every time a new ultra high-resolution display panel emerges, a transfer rate that the new panel needs must be realized. To be more specific, a new video interface timing must be defined, LSIs coping with a high transfer clock rate must be newly expanded and a new multi-channel structure must be adopted for the video interface signals. Then, the above must be added to Video Interface Standard such as VESA (Video Electronics Standard Association). Infrastructure for effectively promoting these new expansions, and for introducing new standards, is now almost never ready, and this is the main impediment to the spread of display systems using the ultra high-resolution display panels, in spite of the near-future demands for the ultra high-resolution display panels. As long as a video interface is newly expanded according to conventional interface extension techniques, these problems will persist. To solve these problems thoroughly, a video interface based on a different concept from that of the conventional video interface must be devised.